Hi Viktor, Thanks for the clarification. You are absolutely right, I must be mixing up SSL and SASL. I'll make sure that it is clear to me tonight.
You are also right that openrelay.customer.com has a non-working STARTTLS. They actually have neither authentication nor encryption. This is actually my current 'challenge': how to set this relay up without encryption and authentication while keeping our current config for other relays (encryption + authentication). Emmanuel On 22.10.18, 18:36, "Viktor Dukhovni" <owner-postfix-us...@postfix.org on behalf of postfix-us...@dukhovni.org> wrote: > On Oct 22, 2018, at 11:01 AM, Emmanuel Jaep <emmanuel.j...@gmail.com> wrote: > > I just tried the configuration you were proposing: > Main.cf > mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 openrelay.customer.com > smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination Those are Postfix SMTP *server* settings that only affect *inbound* email. > But I keep on getting: > postfix/smtp[2540]: SSL_connect error to openrelay.customer.com [xx.xx.xx.xx]:25: -1 > postfix/smtp[2540]: warning: TLS library problem: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c These are logs from the Postfix SMTP *client*, trying to send *outbound* email. They are completely unrelated. > I believe that the parameters > smtpd_use_tls=yes This is an unrelated *server* setting. > smtp_sasl_auth_enable = yes This enables SASL outbound, but can't possibly cause TLS/SSL connection problems. DO NOT confuse SSL and SASL. > are forcing to use sasl... No. The real issue is that "openrelay.customer.com" has non-working STARTTLS. -- Viktor.